gistfile1.js

    var setupEllipsis = function(container, itemIndex, itemCount, maxItemCount) {

        // Make everything visible
        var hidden = container.all('li.hidden');
        hidden.removeClass('hidden');
        var ellipsis = container.all('li.ellipsis');
        ellipsis.removeClass('ellipsis');

        // Get the bounding box data for the selected item
        var activePage = container.one('li.pageNum-'+itemIndex);
        var ellipL = Y.Util.getClassValue(activePage, 'ellipL');
        var ellipU = Y.Util.getClassValue(activePage, 'ellipU');
        var ellipM = Y.Util.getClassValue(activePage, 'ellipM');

        var prevHidden = false;

        var pages = container.all('li.pageNav');
        pages.each(function (pageButton) {
                curItemIndex = Y.Util.getClassValue(pageButton, 'pageNum');
                if (curItemIndex == 0 ||
                    (curItemIndex >= ellipL &&
                     curItemIndex <= ellipU) ||
                    curItemIndex == ellipM) {
                    // You're visible
                    prevHidden = false;
                }
                else {
                    if (!prevHidden) {
                        pageButton.addClass('ellipsis');
                        prevHidden = true;
                    }
                    else {
                        pageButton.addClass('hidden');
                    }
                }
            });
    }